1/8 NPT coming out of the trans.
The coolers seem to vary...........my last B&M was 3/8 NPT .
I have a Derale going in my current project that has 1/2 NPT.
-6 line...........I used the PTFE / stainless on the Dart and they require a generous radius for bends , but it never presented a problem.
I am using conventional braided stainless on the Volare.
Don't waste your time with barbed fittings and clamps.
And I know they work and have worked for years.
But when they fail , it is spectacular.
Not a gamble I am willing to take.